No, I didn't watch Summer League, and to me it's a no-win: either you look good in Summer League and it can be dismissed, or you can look bad and it's really concerning. So with that perspective, at least both Doug McDermott and Tony Snell didn't look bad.
In fact, they were voted as among the 5 best in the whole 'league'. So, good! But you can also look at last year's first-team and see it's not that exciting of an honor. Heck, just read this from last year.
The SummerBulls played 5 games last week, losing the 5th probably not coincidentally as Doug McDermott was rested for that one. Snell was 5th in scoring at 20ppg on 46% shooting. McDermott was a bit below him at 18ppg. Most impressively, they were a combined 29/61 from three (47.5%).
And I did see this one bit from McDermott, 2 blocks and a pull-up 3 vs. Philadelphia. I believe that eclipsed his college career block total. I then turned the channel as to remember his performance as pristine.
For a lot more on McDermott and his Summer League performance, Rob Mahoney had a feature at SI.com detailing the type of plays McDermott had been running, and how it puts pressure on the defense. Throughout the draft process there were lots of concerns about McDermott's lack of ancillary skills (i.e. the extreme lack of blocks, as mentioned above), but if the dude can shoot like this, it may not matter: it won't be about the Bulls worrying about which lineup to put McDermott in, it'll be on other teams worrying about him.